Premature ventricular contractions (PVCs) coexist in patients with heart failure (HF) and LV dysfunction. Frequent PVCs have shown to induce a reversible cardiomyopathy (PVC-CM). Yet, it is unclear why some patients develop PVC-CM, while others do not. Retrospective and observational studies have shown improvement of LV function after PVC suppression via radiofrequency ablation (RFA). Thus, appropriate diagnosis and treatment of patients with PVC-CM is believed to carry significant benefits, improving quality of life (QOL), HF symptoms / admissions and life expectancy. Currently, these patients are offered RFA, antiarrhythmic drugs (AADs) or no treatment depending on physician?s experience and resources. Thus, there is clear need for a large clinical trial comparing these treatment strategies. Yet, we need to better understand prevalence of PVC-CM, feasibility and limitations of such a trial. The long-term objectives of this study are to: 1) identify the best treatment strategy to suppress PVCs and improve PVC-CM, 2) compare the clinical benefits (quality of life, HF symptoms / admissions and adverse events) between RFA and AADs, and 3) identify patients and PVC features that predispose to the development of PVC- CM. The specific aims of the proposed pilot study include: 1) estimate the prevalence of PVC-CM in population receiving Holter monitors and 2) assess the feasibility and better design and power of a full scale large randomized study. We hypothesize that RFA has significant clinical benefits, besides improvement in CM with better outcomes and lower complications at 1 year when compared to AADs. Our pilot study hypothesizes that the prevalence of PVC-CM is underestimated and conducting a large randomized trial is feasible. Research Design and Methods. We propose to screen 20,000 consecutive ambulatory ECG Holter monitors of all participating centers to identify all patients with probable diagnosis of PVC-CM (PVC burden >10% and LVEF <45%). In addition, we will conduct a clinical pilot study, enrolling 30 patients with frequent PVCs (burden >10%) and CM (LVEF <45%) and randomize them to either: 1) RFA or 2) AADs. Prior to treatment, all patients will undergo a baseline cardiac MR and be allowed a 3-month observation period (optimal HF medical therapy). We plan to follow change in LV function/scar, PVC burden/arrhythmias and clinical/functional status (QOL, HF symptoms and admissions, NYHA class) and adverse events throughout the observation period and compare with PVC suppression strategies (RFA or AAD). Similar comparison will be made between RFA and AAD treatment groups during a 12-month follow up using a Prospective Randomized Open, Blinded End-point (PROBE) study design. The treatment regimens will be compared in an intention-to-treat analysis. This pilot study is intended to estimate the prevalence of this clinical entity and pave the way for a large full scale randomized trial to identify best treatment strategy for patients with PVC-CM. Treating and reversing this underestimated PVC-CM may improve patient?s health and subsequently decrease HF healthcare spending.